Brake Warning Switch

[Byrdock]

Has anyone had any luck finding a replacement pressure switch for the front proportioning valve? The one on my new truck leaks. Looks like the epoxy in the top has disappeared, has anyone ever repaired one?

[Eagle]

There is no epoxy in the front metering block. All seals are O-rings.

[Byrdock]

There wasn't an O-ring under the plastic switch but I found one to fit the piston in the plastic switch, but I still have brake fluid seeping out the top of the switch. Might have to see if I can find a thicker O-ring and see if that works. I just figured there might have been some kind of sealer in top of the switch to keep it air-tight.

[Eagle]

There wasn't an O-ring under the plastic switch but I found one to fit the piston in the plastic switch, but I still have brake fluid seeping out the top of the switch. Might have to see if I can find a thicker O-ring and see if that works. I just figured there might have been some kind of sealer in top of the switch to keep it air-tight.

So you're not talking about the metal metering block itself, you're talking about the plastic switch that triggers the brake warning light? There shouldn't be any brake fluid getting to that -- the slider is sealed on both sides of it with O-rings.

 

[Byrdock]

Thanks Eagle, that's what I've been searching for. Do you know if there is a rebuild kit or do I just find standard O-rings for a rebuild?

[Eagle]

Dunno.

 

If you want to try a rebuild, be sure you get O-rings made from a rubber that's resistant to brake fluid.